Gene therapy makes advances in blood-cancer treatment
Doctors say the treatment, which transforms cancer patients’ blood cells into those that fight against the disease, could become the first approved in the United States and the first for cancer worldwide.
The Associated Press
In one of the biggest advances against leukemia and other blood cancers in many years, doctors are reporting unprecedented success by using gene therapy to transform patients’ blood cells into soldiers that seek and destroy cancer.
A few patients with one type of leukemia were given this one-time, experimental therapy several years ago, and some remain cancer-free. At least six research groups have treated more than 120 patients with many types of blood and bone-marrow cancers, with stunning results.
“It’s really exciting,” said Dr. Janis Abkowitz, blood-diseases chief at the University of Washington in Seattle and president of the American Society of Hematology. “You can take a cell that belongs to a patient and engineer it to be an attack cell.”
In one study, all five adults and 19 of 22 children with acute lymphocytic leukemia, or ALL, had complete remission, meaning no cancer could be found after treatment, although a few have relapsed since then.
These were gravely ill patients out of options. Some had tried multiple bone-marrow transplants and as many as 10 types of chemotherapy or other treatments.
Cancer was so advanced in Emily Whitehead, 8, of Philipsburg, Pa., that doctors said her major organs would fail within days. She was the first child given the gene therapy and shows no sign of cancer nearly two years later.
Results on other patients with myeloma, lymphoma and chronic lymphocytic leukemia, or CLL, will be reported at the hematology group’s conference that started Saturday in New Orleans.
Doctors say this has the potential to become the first gene therapy approved in the United States and the first for cancer worldwide. Only one gene therapy is approved in Europe, for a rare metabolic disease.
The treatment involves filtering patients’ blood to remove millions of white blood cells called T-cells, altering them in the lab to contain a gene that targets cancer, and returning them to the patient in infusions over three days.
“What we are giving essentially is a living drug,” permanently altered cells that multiply in the body into an army to fight the cancer, said Dr. David Porter, a University of Pennsylvania scientist who led one study.
Several drug and biotech companies are developing these therapies. Penn has patented its method and licensed it to Switzerland-based Novartis. The company is building a research center on the Penn campus in Philadelphia and plans a clinical trial next year that could lead to federal approval of the treatment as soon as 2016.
Talking with the researchers, “there is a sense of making history ... a sense of doing something very unique,” said Hervé Hoppenot, president of Novartis Oncology, the division leading the work.
Lee Greenberger, chief scientific officer of the Leukemia and Lymphoma Society, agreed. “From our vantage point, this looks like a major advance,” he said. “We are seeing powerful responses ... and time will tell how enduring these remissions turn out to be.”
The group has given $15 million to various researchers testing this approach. Nearly 49,000 new cases of leukemia, 70,000 cases of non-Hodgkin lymphoma and 22,000 cases of myeloma are expected to be diagnosed in the United States in 2013.
Many patients are successfully treated with chemotherapy or bone-marrow or stem-cell transplants, but transplants are risky, and donors can’t always be found. So far, gene therapy has been tried on people who were in danger of dying because other treatments failed.
The gene therapy must be made individually for each patient, and lab costs are about $25,000, without a profit margin. That’s still less than many drugs used to treat these diseases and far less than a transplant.
Penn doctors have treated the most cases so far — 59. Of the first 14 patients with CLL, four had complete remissions, four had partial ones and the rest did not respond. However, some partial responders continue to see their cancer shrink a year after treatment.
“That’s very unique to this kind of therapy” and gives hope the treatment may still purge the cancer, said Porter. An additional 18 CLL patients were treated; half have responded.
Penn doctors also treated 27 ALL patients. All five adults and 19 of the 22 children had complete remissions, an “extraordinarily high” success rate, said Dr. Stephan Grupp at the Children’s Hospital of Philadelphia.
Six have since relapsed, though, and doctors are pondering a second gene-therapy attempt.
At the National Cancer Institute, Dr. James Kochenderfer and others have treated 11 patients with lymphoma and four with CLL, starting roughly two years ago. Six had complete remissions, six had partial ones, one has stable disease and it’s too soon to tell for the rest.
Patients are encouraged that relatively few have relapsed.
“We’re still nervous every day because they can’t tell us what’s going to happen tomorrow,” said Tom Whitehead, Emily’s father.
Doug Olson, 67, a scientist for a medical-device maker, shows no sign of cancer since gene therapy in September 2010 for CLL he had had since 1996.
“Within one month, he was in complete remission. That was just completely unexpected,” said Porter, his doctor at Penn.
Olson ran his first half-marathon in January and no longer worries about how long his remission will last. “I decided I’m cured. I’m not going to let that hang over my head anymore,” he said.